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Carrier furnace light codes

The Ultimate Guide to Carrier Furnace Light Codes

Are you puzzled by the Carrier furnace light codes and their cryptic messages from your heater? If you have a Carrier furnace in your home or building, you know how…

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Are you puzzled by the Carrier furnace light codes and their cryptic messages from your heater?

If you have a Carrier furnace in your home or building, you know how important it is to keep it running smoothly and efficiently. However, like any other appliance, it can sometimes encounter problems or malfunctions that affect its performance or safety.

One of the ways that a furnace communicates with you is by using these Carrier furnace light codes. They are error codes that indicate the status and problems of the system. They are displayed by flashing lights on the furnace or the thermostat.

In this blog post, we will provide you with the ultimate guide to Carrier furnace light codes. You will learn:

  • How to enter the diagnostic mode on a Carrier Infinity thermostat and how to read the error codes on the screen.
  • How to read a Carrier furnace error code using the flashing LED lights on the furnace or the thermostat.
  • What all the possible Carrier furnace error codes mean and how to troubleshoot them.
  • How to fix some common Carrier furnace problems using the light codes.

By reading this blog post, you will be able to understand and troubleshoot Carrier furnace light codes and fix common problems. This will help you save money, time, and energy, and ensure your comfort and safety.

How to Read and Interpret Carrier Furnace Light Codes

Carrier furnace light codes are a way of communicating the status and problems of your furnace using flashing lights on the furnace or the thermostat. They can help you troubleshoot and fix some common issues with your furnace, such as a defective gas valve solenoid or an open circuit.

Types of Carrier Furnace Light Codes

There are different types of Carrier furnace light codes, depending on the model and the system. Some of the common types are:

  • Yellow light: This light indicates the burner flame mode, which can be either low fire or high fire. Low fire mode is used for normal heating, while high fire mode is used for faster heating when the house is very cold. A continuously flashing yellow light means that the furnace is stuck in high fire mode, which could be caused by a faulty gas valve solenoid.
  • Green light: This light indicates the fan mode, which can be either on or off. The fan mode controls the blower that circulates the air in the house. A rapidly flashing green light means that the blower is on, while a slow flashing green light means that the blower is off.
  • Orange light: This light indicates that there is dirt buildup on the furnace burners, which may interfere with the gas supply and heat production. An orange light is produced by an incorrect ratio of oxygen and furnace gas, which could affect the efficiency and safety of your furnace.
  • Red light: This’s one of the Carrier furnace light codes that indicates that there is a problem with the furnace that requires immediate attention. A red light is usually accompanied by an error code that shows the type and severity of the problem.

How to Access Carrier Furnace Light Codes

To access the Carrier furnace light codes, you need to look at the LED lights on the furnace or the thermostat and count the number of flashes they make. The number of flashes corresponds to a two-digit code that identifies the problem. 

The first digit is the number of flashes by the yellow light, while the second digit is the number of flashes by the green light. 

For example, if you see two flashes by the yellow light and four flashes by the green light, that means code 24, which indicates a secondary voltage fuse is open.

You can also enter the diagnostic mode on a Carrier Infinity thermostat to access the error codes on the screen. To do this, you need to pull down the flip-down door on the bottom of the thermostat and press and hold the advanced button for 10 seconds until you see the install/service menu. 

Then, use the scroll button to get to checkout, which is Carrier’s diagnostic mode. Wait for the system to check all of its components and then highlight service info and select it. If there is a problem with any component of the system, you will see the error code next to it.

READ: What to Do When Your Furnace Light Blinks 3 Times

How to Troubleshoot Carrier Furnace Light Codes

Carrier furnace light codes are two-digit numbers that show the type and state of your furnace. They are determined by the number and color of flashes by the yellow and green lights on the furnace. 

The yellow light indicates the burner flame mode, while the green light indicates the fan mode. The codes can help you troubleshoot and fix some common problems with your furnace, such as a defective gas valve solenoid or an open circuit. 

Carrier furnace light codes are also in different colors of fluorescent tubes to help identify the system, model, and serial number.

Here is a table that summarizes some of the common Carrier furnace light codes and their meanings

CodeMeaning
11No faults detected in recent history
12Blower is on after start-up (gas furnaces) / Blower calibration lockout (electric furnaces)
13Limit circuit/switch lockout
14Ignition lockout
21Gas heating lockout (gas furnaces) / Invalid model selection (electric furnaces)
22Abnormal flame-proving signal (gas furnaces) / Setup error (electric furnaces)
23Pressure switch didn’t open (gas furnaces) / Invalid blower airflow selection (electric furnaces)
24Secondary voltage fuse is open
31Switch in the unit didn’t close or open properly
32Low-pressure switch fault (gas furnaces) / Low voltage detected (electric furnaces)
A table of Carrier furnace light codes and their meaning

Each code has a different significance and indicates a different issue with your furnace. Some Carrier furnace light codes are more serious than others and may require professional assistance. 

For example, code 21 means that your gas heating system is locked out and will not auto-reset. This could be caused by a faulty gas valve or a leaky valve. You should call an authorized HVAC technician to fix this problem. 

On the other hand, code 23 means that your pressure switch didn’t open or that your blower airflow selection is invalid. This’s one of the Carrier furnace light codes that could be caused by obstructed vents, excessive wind, or incorrect A/C or CF switch settings. You can check for these issues yourself and try to resolve them.

READ: How to Troubleshoot and Maintain Your Carrier WeatherMaker 9200 Furnace

Common Problems Carrier Furnace and Solutions

Carrier furnaces are devices that provide heating and cooling to your home or building by using gas or electricity. They are designed to be reliable and efficient, but sometimes they may encounter some issues that affect their performance or safety. 

Some of these issues can be easily fixed by yourself, while others may require professional assistance.

Here are some of the common problems that homeowners may encounter with their Carrier furnaces and how to solve them:

Furnace doesn’t turn on or doesn’t blow hot air

This could be caused by a number of reasons, such as a power outage, a tripped circuit breaker, a faulty thermostat, or a dirty air filter. To fix this, you can check the following steps:

  • Make sure the thermostat is getting power and is set to “heat” mode. If it uses batteries, replace them if needed.
  • Check the circuit breaker or fuse box and make sure the switch for the furnace is on. If it is tripped or blown, reset or replace it.
  • Check the air filter and replace it if it is dirty or clogged. A dirty filter can restrict the airflow and prevent the furnace from heating properly.
  • Check the condensation drain and make sure it is not clogged or frozen. A clogged drain can cause water leakage and damage the furnace.

The furnace cycles on and off frequently 

This could be caused by a dirty air filter, a faulty thermostat, or a blocked vent. To fix this, you can try the following steps:

  • Replace the air filter if it is dirty or clogged.
  • Check the thermostat and make sure it is not affected by external sources of heat or cold, such as sunlight, drafts, or appliances. Adjust the temperature setting if needed.
  • Check the vents and make sure they are not blocked by furniture, curtains, or other objects. Clear any obstructions and allow proper airflow.

Furnace makes loud or unusual noises

This could be caused by loose or worn parts, such as belts, bearings, motors, or fans. To fix this, you can try the following steps:

  • Turn off the power to the furnace and inspect the parts for any signs of damage or wear. Tighten any loose screws or bolts and lubricate any moving parts if needed.
  • Replace any broken or worn parts with new ones. You may need to contact an authorized HVAC technician for this step.
  • Check the blower fan and make sure it is not dirty or obstructed by debris. Clean it with a soft brush or vacuum if needed.

Furnace leaks water 

This could be caused by a clogged condensation drain, a cracked heat exchanger, or a faulty humidifier. To fix this, you can try the following steps:

  • Turn off the power and gas supply to the furnace and mop up any excess water to avoid water damage.
  • Check the condensation drain and make sure it is not clogged or frozen. Clear any blockages with a wire hanger or a wet/dry vacuum if needed.
  • Check the heat exchanger and look for any cracks or holes. If you find any signs of damage, contact an authorized HVAC technician immediately as this could pose a serious health risk.
  • Check the humidifier and make sure it is not leaking or overflowing. Adjust the settings if needed and replace any faulty parts.

Conclusion

In wrapping up this ultimate guide, understanding Carrier furnace light codes is crucial for efficient troubleshooting and maintenance. Armed with this knowledge, you can more confidently approach furnace issues, ensuring a warm and cozy environment. Keep this guide handy for all your Carrier furnace light codes-related queries.

I'm an HVAC enthusiast and a passionate writer dedicated to sharing valuable insights and practical tips about heating, cooling, ventilation, and air conditioning systems.

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Hi there, I'm Robert Brooks

Hi there, I'm Robert Brooks

I’m so glad you are here! Welcome to my website, where I’ll share easiest HVAC troubleshooting tips, buyers guides, and everything about HVAC cooling and heating system. Learn more about me.

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